1. Field of the Invention
The present invention relates to image processing apparatuses, and, more particularly, to an image processing apparatus capable of generating facial expression animations, a processing method for the image processing apparatus, and a program causing a computer to perform the processing method.
2. Description of the Related Art
A technique for generating an animation by computing facial expression changes is generally used in the CG (Computer Graphics) field, and, in particular, is much in demand in the video game field and the field of movie-type special effects. Such a technique is referred to as “facial animation”.
In order to generate an animation, the key frame method is generally used. The key frame method is an animation technique for generating a moving image by specifying the shape or position of an object every several frames and performing interpolation processing between the specified frames. Many applications or libraries used to support animation creation are configured to perform interpolation processing upon key frames specified by a user.
In order to apply such key frame specification for the facial animation, a system mixing various facial expressions and displaying the mixed facial expression on a display screen has been proposed. As an example of the system, there is a technique for interactively displaying a face shape by mixing elements such as fear, anger, and disgust (see, for example, Japanese Unexamined Patent Application Publication No. 2002-197489, FIG. 1).